28V--12V/5A用什么芯片?(不隔离的)

34063外加三极管

YDS512  INPUT 14-35V   OUT 12V  5A  
5.00元/只  (不隔离,共地)
YDS112      DC/DC (15-35V)/12V 1A                  1000PCS    3.00
YDS105      DC/DC (10-35V)5V 1A                    2000PCS    3.50
YDS212      DC/DC (15-35V)/12V 2A                  2000PCS    3.50
YDS205      DC/DC (15-35V) 5V 2A                   1000PCS    4.00
YDS224      DC/DC (26-40V) 24V 2A                   500PCS    4.00
YDSR3V3     DC/DC (7-35V) 3.3V 3A                  2000PCS    4.50
YDS305      DC/DC (7-35V) 5V 3A                    2000PCS    4.50
YDS312      DC/DC (15-35V)/12V 3A                  2000PCS    4.50
YDS512      DC/DC (15-35V)/12V 5A                  2000PCS    5.00
宁波市东林电子商行     邬幼川
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用TL494

YDS512 是输入15V-35V  输出12V 5A 很简单 (只要在输入,输出加两只电解就OK了)
1127809926.txt

用BUCK,384*+MOS效率可以达到90%以上

请问那电路的短路好做吗?